Kinf of yarn comprising bamboo fiber and the processing method thereof

ABSTRACT

A yarn comprising natural bamboo fiber and the method for producing the same is disclosed, wherein said yarn is prepared by spinning natural bamboo fibers alone or in combination with other fibers in a blended ratio of natural bamboo fibers comprising 30 to 100% by weight and other fibers comprising 70 to 0% by weight.

TECHNICAL FIELD

The present invention relates to yarn and the method for producing thesame, specifically the yarns comprising pure natural bamboo fiber aloneor in combined with other textile fiber as well as the method forproducing the same.

BACKGROUND

Bamboo possesses a long and ancient history in China. It has not onlybeen given recognition by the writers and arts in history, but alsooffered people abundant resources for their life including clothes,food, household goods, vehicles, and entertainment. The wide applicationof bamboo in people's working, life and activity etc. has been thoughtmuch of by people all over the world. Nowadays, bamboo concerns peopleclosely in their everyday life and plays an important role in societyeconomic construction. While recently, it is a new topic for discussionin the application of bamboo resource that natural bamboo fiber can beused to spin and weave. As a natural fiber that comes from a greenplant, with abundant resource and fine quality, bamboo fiber is a classof new and natural fiber. The exploitation and application of bamboo intextile industry is an important task that shows historic significanceand social interest. Therefore, many enterprises and people onscientific research have been seeking for the aim on how to make thenatural bamboo textile product going on wheels as soon as possible, nomatter on scientific research, on manufacture and on sales market. Thetwenty-first century is an era seeking environment protecting. Naturalbamboo fiber, as a kind of new green environment friendly natural fiber,takes on un-resistant attraction. That is not only for its green andnatural, but due to its unique merits in the properties such asanti-bacteria, wearability, moisture absorption and gas permeabilitythat other fibers don't have. On the basis that there is uncountablelumen distributing on the cross section of bamboo fibers, bamboo fiberscan absorb or evaporate moisture instantly. Therefore, “Breathing Fiber”is a name given to natural bamboo fiber. People would favor bamboofibers as a new material of textile. The so-called “bamboo fibers”textiles in the market at present are exactly articles made of viscosefibers produced from bamboo pulp sheets (China Patent No. ZL02113106.6).The characteristic of natural bamboo fibers in such bamboo rayon producthas been greatly destroyed and the bamboo fibers existed in yarns haveessentially lost the excellent characteristic of natural bamboo fibers,thus, the authoritative organization don't admit that the bamboo rayonproduct is an article of natural bamboo fibers.

China Patent No. ZL02111380.7 disclosed a process to produce realnatural bamboo fibers that can efficiently keep the excellent merits ofbamboo fibers. To differentiate the fiber from the rayon one, the fiberis called natural bamboo fiber. The success in getting natural bamboofiber laid a good foundation of manufacturing natural bamboo textileproducts. However, the fibers produced according to the process of thispatent cannot be directly used in spinning, for the reason of its poorcohesion, low yarn strength and being changed much with the environment.There are many technical problems to be solved on how to produce yarnsand fabric with natural bamboo fibers. There still exist the need to domore research work on bamboo fibers.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a natural bamboo yarnsthat can not only keep the original characteristics of natural bamboofibers, but also meet the demands of textile products. Another object ofthe present invention is to provide the process for producing thenatural bamboo yarns.

The above objects of the present invention are achieved by the followingmeans. Firstly, impurities such as lignin and pectin are removed frombamboo (generally Mao bamboo) by treating it with natural agent. In oneembodiment, the obtained fiber is the natural bamboo fiber in a state offilament that is produced according to the process as disclosed in ChinaPatent No. ZL02111380.7. In another embodiment, the obtained fiber isthe natural bamboo fibers in a state of processed fibers formed byremaining a certain amount of lignin and pectin on purpose. In order toimprove the spinning properties of natural bamboo fibers and strengthenthe properties of dispersion and collecting, the natural bamboo fibersare further subjected to a treatment which can improve the spinnability.The natural bamboo fibers are treated by providing oil (emulsificationoil) and then drying. Then, the obtained fibers are treated byhumidifying and providing oil. The natural bamboo fibers which can bespun are thereby obtained after stacking a period of time. Spinning ofthe natural bamboo fibers can be conducted alone or in combination withother textile fibers. Various pure natural bamboo yarns or blendingyarns can be obtained by the process such as ramie spinning system,cotton spinning system, silk spinning system, wool spinning system orlinen spinning system. The main technical points of the presentinvention are as following:

(1) The yarn is prepared by spinning natural bamboo fibers alone or incombination with other fibers (such as terylene, nitrile, ramie, wool,Tencel, rayon, cotton, silk and modal etc) in a blended ratio of naturalbamboo fibers comprising 30 to 100% by weight and other fiberscomprising 70 to 0% by weight.

(2) In said yarn, said natural bamboo fiber comprises a natural bamboofiber in a state of filament, or a natural bamboo fibers in a state ofprocessed fibers formed by remaining a certain amount of lignin andpectin on purpose.

(3) In said yarn, said natural bamboo fiber mainly has the followingtechnology index: the natural bamboo the natural bamboo fiber in a statefibers in a state of filament of processed fibers fiber count 1200Nm˜2000 Nm more than 500 Nm fiber strength 3˜5.5 CN/D 3˜5.5 CN/D averagefiber length 30˜100 mm 30˜100 mm nep less than 5/g thick ratio less than0.5%

(4) The process for manufacturing the natural bamboo yarn comprisespreliminary producing step of the natural bamboo fiber (according toknown technology), the step of improving the spinnability of naturalbamboo fiber and the step of spinning. It should be noted that the stepof improving the spinnability of natural bamboo fiber is the mostimportant.

(5) In the above-mentioned process, the step of improving thespinnability of natural bamboo fiber comprising:

-   -   a. obtaining natural bamboo fiber according to known technology        such as disclosed in China Patent No. ZL02111380.7;    -   b. selecting natural bamboo fiber; in which        -   the requirements for selecting natural bamboo fiber are that            the fiber should be straight and order; wherein the            technology index of the natural bamboo fiber are consistent            with those cited in the above item (3);        -   wherein the weight of fiber bundle changes in various            species;    -   c. providing oil to the natural bamboo fiber; in which        -   the oil is a mixture of soap with emulsification oil,            wherein the amount of emulsification oil is 1 to 1.8% by            weight and the amount of soap is 0.5 to 0.9% by weight, both            based on the weight of natural bamboo fiber; the oil is            provided by immersing the fiber into oil after humidifying            treatment at a temperature of 80˜90° C. for 3˜4 hours in a            bath ratio of 1:6˜8; wherein the emulsification oil            comprises 47˜53% by weight of plant oil, 0.04˜0.06% by            weight of sodium hydroxide and 47˜53% by weight of water;            and said plant oil has a acid number of less than 8, a            saponification number of 185˜195 and an iodine value of            76˜83;    -   d. drying the natural bamboo fiber in dryer after dehydrating        it, the moisture regained after drying is 5˜9% by weight;    -   e. humidify by spraying and providing oil for the natural bamboo        fiber after the drying step, wherein the oil comprises 9˜10.6%        by weight of kerosene, 0.3˜0.5% by weight of sodium carbonate,        6˜7.6% by weight of plant oil and 83˜84% by weight of water;    -   f. stacking the natural bamboo fiber for 5˜7 days after        humidifying, the moisture of the fiber regained is 10˜15%.

(6). Spinning the natural bamboo fiber by the methods selected from thegroup consisting of:

-   -   i. the technology of ramie spinning system in which the length        of fiber is from 70 mm to 100 Mm, as shown in FIG. 1.    -   ii. the technology of cotton spinning system in which the length        of fiber is from 30 mm to 50 mm, as shown in FIG. 2.    -   iii. the technology of silk spinning system in which the length        of fiber is from 65 mm to 100 mm, as shown in FIG. 3.    -   iv. the technology of wool spinning system in which the length        of fiber is from 65 mm to 100 mm, as shown in FIG. 4.    -   v. the technology of linen spinning system in which the length        of fiber is from 50 mm to 100 mm, as shown in FIG. 5.

(7). the draw ratio is controlled between 5 and 10 in the step ofslivering, drawing and roving;

(8). in the slivering step, fiber is fed at low speed, with little fixquantity and proper tension. The treatment aims to align fiber furtherand avoid fiber damage.

(9) in the combing step, fiber is fed at low speed, with little fixquantity. Different technology scheme is used depend on differentmaterial quality. The draw gauge is 28˜48 mm. The treatment aims toeliminate short fiber and some faults so as to get higher count yarn.

(10) in the drawing step, sliver is fed at low speed, with little fixquantity, weighty press, small diameter cone-shaped. The treatment aimsto improve the sliver evenness and smoothness, ensure uniform mixing andmake it shaped well.

(11). in the roving step, sliver is fed at low speed, with little fixquantity, higher twist, keep soft and no-broken.

(12) in the spinning step, sliver is fed at low speed, with little drawforce, given proper press and proper tension and draw gauge. Thetreatment aims to decrease hair, reduce breaking, increase yarnregularity and reduce strength unevenness.

(13). During spinning step, a high environmental temperature andhumidity is kept. For example, the temperature is from 22 to 30° C. andthe relative humidity is from 70 to 90%;

(14). the draw ratio is controlled between 10 and 30 in spinning step(changing with species);

(15). doubling and twisting natural bamboo fiber yarn or bamboo blendedyarn, forming multiplied yarn (changing with the use of article);

(16). In general, the natural bamboo fiber and other fibers are blendingby sliver blended, little fix quantity blended or bundle blended.

Natural bamboo yarn and bamboo blended yarn produced according to thepresent invention have excellent gloss and high strength after evaluatedthe properties of natural bamboo fiber. The fineness of the naturalbamboo fiber in a state of filament is in the range of about 1200 to2000 denier, and the fineness of the natural bamboo fibers in a state ofprocessed fibers is about 500 denier and more. The length of fiber canbe changed depend on specific requirement. Numerous fine grooves existedon the surface of the natural bamboo fiber are advantageous to improvethe function of moisture absorption and moisture evaporation. Fine gapsbetween the fibers are kept no matter bend and press the fiber and thuscapillary effect is maintained in any cases. Therefore, it is verysuitable to use it as fabrics in spring clothing and summer clothing.The use of natural bamboo fiber in summer clothing is advantageous tovaporize sweat from body surface and avoid the comfortlessness resultedfrom sweating. Furthermore, the evaporation of sweat can remove heatfrom body surface. The raw material bamboo used in the present inventionis widely grown in Asia such as in China and Japan and is readily toobtain. The yarn comprising natural bamboo fiber according to thepresent invention is environment-friendly and biodegradable.

Moreover, the natural bamboo fibers can be spun alone or in combinationwith other fibers. The obtained yarns comprise 36 Nm pure natural bamboofiber yarn for weaving or knitting, 24 Nm pure natural bamboo fiber yarnfor weaving or knitting, 45 Nm blended yarn of natural bamboo fiber andwater-soluble fiber (74% natural bamboo fiber and 40% water-solublefiber), 68 Nm blended yarn of natural bamboo fiber and terylene (35%natural bamboo fiber and 65% terylene), 51 Nm blended yarn of naturalbamboo fiber and ramie (70% natural bamboo fiber and 30% ramie), 13.5 Nmpure natural bamboo fiber knot yarn, 80 Nm blended yarn of naturalbamboo fiber and silk (50% natural bamboo fiber and 50% silk), 50 Nm/2blended yarn of natural bamboo fiber and wool (60% natural bamboo fiberand 40% wool), and 15 Nm pure natural bamboo fiber yarn.

ILLUSTRATION OF THE FIGURES

FIG. 1 is a schematic diagram of a process in which ramie spinningsystem is used according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a process in which cotton spinningsystem is used according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a process in which silk spinning systemis used according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a process in which wool spinning systemis used according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a process in which linen spinningsystem is used according to an embodiment of the present invention.

EXAMPLES Example 1

The Production of 24 Nm Pure Natural Bamboo Yarn

The treatment conditions according to the technology of ramie spinningsystem are described as below.

1. obtaining natural bamboo fiber according to known technology such asdisclosed in China Patent No. ZL02111380.7;

2. improving the spinnabitity of natural bamboo fiber;

-   -   A. providing oil to the natural bamboo fiber; in which        -   the oil is provided by immersing the fiber into oil after            humidifying treatment at a temperature of 80˜90° C. for 3˜4            hours in a bath ratio of 1:6˜8, wherein the amount of            emulsification oil is 1.4% by weight and the amount of soap            is 0.8% by weight, both based on the weight of natural            bamboo fiber.        -   wherein the emulsification oil comprises 49.95% by weight of            tea oil, 0.05% by weight of sodium hydroxide and 50% by            weight of water. And the tea oil has a acid number of less            than 8, a saponification number of 185˜195 and an iodine            value of 76˜83.    -   B. Dehydrating and drying the natural bamboo fiber, the moisture        regained after drying is 5˜9%.    -   C. humidify by spraying and provide oil for the natural bamboo        fiber after the drying step, wherein the oil comprises 10% by        weight of kerosene, 0.4% by weight of sodium carbonate, 6.6% by        weight of tea oil and 83% by weight of water.    -   D. stacking the natural bamboo fiber for 5˜7 days after        humidifying, the moisture of the fiber regained is 10˜15%.

3. selecting the fiber after humidifying and stacking the fiber;

The weight of bundle of fiber after selecting is 65±5 g and therequirements for selecting are as follows:

-   Count: 1200˜2000 Nm;-   Strength: 4˜5.5 CN/D-   Average length: 80˜100 mm-   Factor of changing length: 40-45%-   Nep: less than 5/g-   Thick: less than 0.5%

4. Spreading the bundle of fiber twice under the condition of:

-   Spreading machine: 225 g/kont-   Needle comb strike times: 409/minute-   Needle comb specification: 18 needles/inch-   Draw ratio at the back: 1.017

5. Slivering the bundle of fiber under the condition of:

-   Needle comb strike times: 390/minute-   Needle comb specification: 18 needles/inch-   Draw ratio at the back: 0.97-   Draw ratio in the front: 1.095

6. Pre-drawing the bundle of fiber under the condition of:

-   Needle strike times: 390/minute-   Needle comb specification: 13˜18 needles/inch-   Draw ratio at the back: 1.02-   Draw ratio in the front: 1.04-   Weight of outlet sliver: 40˜45 g/5 m

7.Combing after pre-drawing under the condition of:

-   Speed of cylinder: 90˜95 /minute-   Draw gauge: 38˜48 mm-   Weight of outlet sliver: 40˜45 g/5 m

8.Drawing the bundle of fiber under the same condition as those in item6.

9. First roving under the condition of:

-   Speed of front roller: 175 rpm-   Speed of spindle: 300 rpm-   Twist factor: 21-   Draw ratio: about 8

10. Second roving under the condition of:

-   Speed of front roller: 58˜70 rpm-   Speed of spindle: 450 rpm-   Draw ratio: about 8

11. Spinning under the condition of:

-   Speed of front roller: 99 rpm-   Speed of spindle: 6250 rpm-   Draw ratio: 17

In this example, natural bamboo fiber bundles are prepared by selecting,arranging, spreading, slivering, pre-drawing and combing the naturalbamboo fiber by means of ramie spinning device after said fiber beingtreated to improve spinnability, and then yarns are prepared by drawing,roving and spinning.

EXAMPLE 2

The Production of 60 Nm Blended Yarn of Natural Bamboo Fiber andWater-Soluble Fiber

The blend ratio of the yarn is 60% natural bamboo fiber and 40%water-soluble fiber.

The treatment conditions according to the technology of ramie spinningsystem are described as below.

1. obtaining natural bamboo fiber according to example 1.

-   -   The requirements for selecting natural bamboo fiber are that the        fiber should be straight and order, and the thick fault is less        than 0.3%. The weight of fiber bundle changes in various        species.

2. improving the spinnabitity of natural bamboo fiber according toexample 1.

3. selecting the fiber after humidifying and drying the fiber

-   -   The weight of bundle of fiber after selecting is 65±5 g.

4. Spreading the bundle of fiber twice under the condition of:

-   First spreading:-   Knotting: 225 g/knot-   Needle comb specification: 18 needles/inch-   Needle comb strike times: 409/minute-   Second spreading:-   Knotting: 225 g/knot-   Needle comb specification: 18 needles/inch-   Needle comb strike times: 409/minute

5. Slivering the bundle according to example 1 under the condition of:

-   Sliver weight: 45˜50 g/5 m-   Needle comb specification: 18 needles/inch-   Needle comb strike times: 309/minute

6. Drawing the natural bamboo fiber sliver together with water-solublefiber sliver under the same condition as in Example 1.

-   -   The water-soluble fiber sliver has a count of 6000 Nm and more,        and an average length of 90 mm and more.    -   Dissolving temperature: starting to dissolve at 88° C. and        dissolved completely at 100° C .

7. Roving the blended sliver

-   -   The sliver is fed at low speed, with little fix quantity,        suitable twist, keep soft and no-broken.

8. Spinning

-   -   Sliver is fed at low speed, with little draw force, given proper        press and proper tension and draw gauge. The treatment aims to        decrease hair, reduce breaking, increase yarn regularity and        reduce strength unevenness.

9. During spinning step, a high environmental temperature and humidityis kept.

-   -   For example, the temperature is from 22 to 30° C. and the        relative humidity is from 70 to 90%.    -   Drawing ratio in slivering, drawing and roving steps is about 8        or more and the drawing ratio in spinning step is about 15˜20.

EXAMPLE 3

The Production of 13.5 Nm Pure Natural Bamboo Yarn

-   -   The treatment conditions according to the technology of cotton        spinning system are described as below.

1. obtaining natural bamboo fiber according to example 1.

-   -   The natural bamboo fiber (short spin technology) has a fiber        count of 1200˜2000 Nm, a fiber strength of 3˜5.5 CN/D, an        average length of 30˜50 mm and a thick faults of less than 1%.

2. improving the spinnabitity of natural bamboo fiber according toexample 1.

3. packing the treated natural bamboo fiber.

4. rolling the fiber on the scutching machine under the condition of:

-   -   The gauge between dust bar is 7 mm    -   The gauge between striker and dust bar (inlet/outlet) is 8 mm/18        mm    -   Speed of the cotton roll roller: 13 rpm    -   Speed of the striker: 1000 rpm    -   The dry measured amount of cotton roll: 400 g/m

5. carding the rolled natural bamboo fiber into sliver in cardingmachine under the condition of:

The gauge between needle roller and dust blade: 15/1000 (inch)

-   -   The gauge between cylinder and needle roller: 7/1000 (inch)    -   The gauge between cylinder and flat (from inlet to outlet) is        14/1000 inch, 12/1000 inch, 12/1000 inch, 12/1000 inch and        14/1000 inch respectively    -   The gauge between cylinder and doffer: 5/1000 inch    -   Doffer speed: 16.6 rpm    -   Cylinder speed: 360 rpm

-   Needle roller speed: 1070 rpm

-   Flat speed: 177 mm/min

-   The dry measured amount of outlet sliver: 24 g/5 m

6. The main technology parameters in drawing are:

-   The number of the slivers fed in: 8-   The dry measured amount of outlet sliver: 21˜22.5 g/5 m-   Draw ratio: 7˜9-   Speed of the front roller: 1300˜1470 rpm-   The gauge in the front: 14 mm-   The gauge at the back: 22 mm

7.The main technology parameters in roving are:

-   The dry measured amount of outlet sliver: 10.2 g/10 m-   Twist factor: 37.2-   Speed of the front roller: 157 rpm-   Spindle speed: 480 rpm-   Draw ratio at the back: 1.18

8.The main technology parameters in spinning are:

-   Twist factor: 140-   Draw ratio at the back: 1.33-   Speed of the front roller: 176 rpm-   Spindle speed: 7330 rpm-   Gauge between two roller center:    -   From front roller to middle roller: 45 mm    -   From front roller to back roller: 100 mm-   Slip notch: 15×0.7 mm for normal yarn    -   -   15×2 mm for slub yarn            the type of equipment that can produce slub is YTC83-SM

9. the main technology parameters in rotor spinning are:

-   Comb roller speed: 7500 rpm-   Rotor speed: 3100 rpm-   Sector angle in separating plate: 45°-   the type of needle roller: OK40-   Twist factor: 150

10. Cotton length bamboo natural fiber and other cotton length fiber areblended by pack blending or sliver blending.

11. During spinning step, a high environmental temperature and humidityis kept. For example, the temperature is from 20 to 30° C. and therelative humidity is from 60 to 80%.

12. The principle of opening and cleaning is to loose fiber, not to beatfiber.

13. The carding is characterized in low speed, mainly aiming to transferfiber and the carding gauge is relatively wide to avoid the damage offiber.

14. In the drawing step, in order to increase the sliver evenness, thesliver is fed in low speed, with weighty press and the draw ratio is alittle more than the number of drawing sliver.

15. The twist factor of roving and spinning is slightly high in favor ofimproving the strength of yarn.

16. The roller in drawing frame and roving frame and spinning frameshould be covered with complex elasticity textile to decrease the fiberinwinded.

In this example, filaments produced during the combing step or filamentsproduced as required by spinning are subjected to clear, scotch, roll,comb, draw, rove and spin (or rotor spinning) by means of cottonspinning device.

EXAMPLE 4

The Production of 80 Nm Blended Yarn of Natural Bamboo Fiber and SilkFiber

The blend ratio of the yarn is 50% natural bamboo fiber and 50% silkfiber.

The treatment conditions according to the technology of silk spinningsystem are described as below.

1. obtaining natural bamboo fiber according to example 1.

-   -   The requirements for selecting natural bamboo fiber are that the        fiber should be straight and order, and the thick fault is less        than 0.3%. The weight of fiber bundle changes in various        species.

2. improving the spinnabitity of natural bamboo fiber according toexample 1.

3. selecting the fiber after humidifying and drying the fiber

-   -   The weight of bundle of fiber after selecting is 65±5 g.

4. Spreading the bundle of fiber twice under the condition of:

-   First spreading: Knotting: 200 g/kont-   Needle comb specification: 18 needles/inch-   Needle comb strike times: 409/minute-   Second spreading: Knotting: 200 g/knot-   Needle comb specification: 18 needles/inch-   Need comb strike times: 409/minute

5. Slivering the bundle according to example 1 under the condition of:

-   Outlet sliver weight: 40˜45 g/5 m-   Needle comb specification: 18 needles/inch-   Needle comb strike times: 309/minute

6. Pre-drawing once the bundle after slivering under the condition of:

-   Outlet sliver weight: 40˜45 g/5 m-   Needle comb specification: 13 needles/inch-   Needle comb strike times: 390/minute

7. Combing the bundle after pre-drawing under the condition of:

-   Speed of cylinder: 92˜95 /minute-   Draw gauge: 38˜45 mm-   Weight of outlet sliver: 40˜45 g/5 m

8. Pre-drawing under the same condition as in above item 6.

9. Blending with the silk and drawing under the condition of:

-   Draw ratio at the back tension: 0.96-   Draw ratio in the front tension: 1.02-   Needle comb strike times: 390/minute-   Need comb specification: 13˜16 needles/inch

10. Roving under the condition of:

-   Outlet count: 3.5˜4 Nm-   Speed of spindle: 55 rpm-   Twist factor: 21-   Draw ratio: about 8 or more

11. Spinning under the condition of:

-   Outlet count: 80 Nm-   Speed of spindle: 6250 rpm-   Twist factor: 80-   Draw ratio: 20˜24

12. During spinning step, a high environmental temperature and humidityis kept. For example, the temperature is from 20 to 30° C. and therelative humidity is from 65 to 80%.

-   -   In this example, natural bamboo fiber bundles are prepared by        spreading, slivering, pre-drawing and combing the natural bamboo        fiber by means of silk spinning device after said fiber being        treated to improve spinnability, and then yarns are prepared by        blending with spun silk, roving and spinning.

EXAMPLE 5

The Production of 50 Nm/2 Blended Yarn of Natural Bamboo Fiber and WoolFiber

-   -   The blend ratio of the yarn is 60% natural bamboo fiber and 40%        wool fiber.    -   The treatment conditions according to the technology of wool        spinning system are described as below.

1. Producing and treating the natural bamboo fiber according to items 1and 2 in example 1.

2. Selecting the natural bamboo fiber after humidifying.

The selected natural bamboo fiber has a fiber count of more than 1500Nm, fiber strength of more than 4 CN/D, fiber average length of 65˜100mm and thick ratio of less than 0.5%.

3. carding the natural bamboo fiber in carding machine to prepare sliverunder the condition of

-   Speed of cylinder: 148 rpm-   Speed of doffer: 15 rpm-   Weight of outlet sliver: 15±1 g/m

4. Pre-drawing the sliver twice under the condition of

-   Needle comb strike times: 800/minute-   Needle comb specification: 7˜10 needles/inch-   Weight of outlet sliver: 11±0.5 g/m

5. Combing the sliver after pre-drawing under the condition of

-   Speed of cylinder: 90˜95 /minute-   Draw gauge: 28˜48 mm-   Weight of outlet sliver: 40˜45 g/5 m

6. Pre-drawing again after combing under the condition of

-   Weight of outlet sliver: 40˜45 g/5 m-   Needle comb specification: 10˜13 needles/inch-   Needle comb strike times: 600˜800/minute

7. Blending natural bamboo fiber sliver with wool sliver after combingand pre-drawing under the condition of

-   draw ratio at the back tension: 1.037-   draw ratio in the front tension: 1.011-   Needle comb strike times : 600˜800/minuter-   Needle comb specification: 13˜19 needles/inch-   The weight of outlet sliver: 20˜45 g/5 m-   Draw ration: 7˜10

8. Roving under the condition of

-   Outlet count: 2.5˜3 Nm-   Speed of spindle: 530 rpm-   Twist factor: 20˜23-   Draw ratio: 10˜12

9.Spinning under the condition of

-   Outlet count: 50 Nm-   Speed of spindle: 5500 rpm-   Twist factor: 90˜100-   Draw ratio: 10˜20

10. Winding under the condition of

-   Speed of yarn: 350˜400 m/minute-   Weight of sheet: 7 g/sheet

11. Doubling under the condition of

-   The number of yarn fed in: two-   Speed of spindle: 6000 rpm-   Twist factor: 130˜150

12. During spinning step, a high environmental temperature and humidityis kept. For example, the temperature is from 20 to 30° C. and therelative humidity is from 70 to 90%.

13. In the spinning step, sliver is fed at low speed, with little drawforce, given proper press and proper tension and draw gauge. Thetreatment aims to increase yarn regularity and reduce strengthunevenness.

In this example, natural bamboo fiber bundles are prepared by slivering,pre-drawing and combing the natural bamboo fiber by means of woolspinning device such as comber after said fiber being treated to improvespinnability, and then yarns are prepared by blending with wool sliver,roving, spinning, grooved drumming, combining and twining.

EXAMPLE 6

The Production of 15 Nm Pure Natural Bamboo Yarn

The treatment conditions according to the technology of linen spinningsystem are described as below.

1. obtaining the natural bamboo fiber in a state of filament or thenatural bamboo fibers in a state of processed fibers.

2. treating the natural bamboo fiber according to item 2 in example 1.

3. Selecting the natural bamboo fiber after humidifying and providingoil.

-   -   The selected natural bamboo fiber has a fiber count of more than        500 Nm, fiber strength of more than 3 CN/D and fiber average        length of 50˜100 mm.

4. the selected fiber is fed in combined breaker and finisher card toprepare sliver under the condition of

-   Speed of the pin apron: 60 m/minute-   Hang-up of apron: 75˜80 times/minute-   Speed of cylinder: 140 rpm-   Speed of doffer: 1012 rpm-   Speed of apron: 1˜1.5 m/minute-   Speed of draw: 25˜30 m/minute-   Width of draw guidance: 52˜72 mm-   Weight of outlet sliver: 10˜15 g/m    -   The technology of carding keeps the principle of beating lightly        and carding lightly, and transferring well and reducing the        damage of fiber as possible.    -   In order to obtain good sliver, draw ratio of every part should        be reduced.

5. Slivering to improve the evenness and strength of the bundle of fiberunder the condition of

-   Number of sliver: 6˜8-   Needle comb strike times: 800˜1000/minute-   Needle comb specification: 7˜10 needles/inch-   Tension draw ratio: 1.015˜1.045

6.Roving under the condition of

-   Outlet count: 11.5 Nm-   Speed of the front roller: 10˜16 m/minute-   Speed of spindle: 500 rpm-   Twist factor: 30˜40

7. Scouring rove under the condition of

-   procedure of roving→scouring→washing in hot water→washing in cool    water.    -   Technology parameter of-   Temperature: 120˜130° C.-   Press: 2 kgf/cm²-   Time: 1.5˜2 hours    -   Washing in hot water at temperature of 60° C. twice and 10˜15        minutes each one.    -   Scouring agents comprises 3˜5% by weight of sodium hydroxide,        0.15˜0.2% by weight of sodium carbonate, 0.3˜0.4% by weight of        sodium metasilicate, 0.3˜0.5% by weight of sodium sulphite and        0.1˜0.2% by weight of penetrant, all based on the weight of        rove.

8. Bleaching rove under the condition of

-   procedure of scouring→acid rinsing→water rinsing→bleaching→water    rinsing

The acid rinsing step is carried out under the condition of acidconcentration of 1˜1.5 g/l, at temperature of normal temperature for10˜15 minutes and then washing in cool water to be clean.

The bleaching step is carried out at temperature of 95˜100° C. for 45˜60minutes and under pH of 10.5˜11, and then washing in hot water attemperature of 50˜60° C. for 10˜15 minutes, finally washing in coolwater for 10˜15 minutes.

Bleaching liquid comprises 4˜5 g/l of hydrogen peroxide, 7˜8 g/lstabilizer, 2˜3 g/l of penetrant and sodium hydroxide.

9. Spinning under the condition of

-   Speed of front roller: 12˜16 m/minute-   Speed of spindle: 5000˜6000 rpm-   Draw ratio: 9˜14-   Twist factor: 95˜115

10. Drying at temperature of 80˜100° C. for 5 hours or more and obtainedmoisture regain is about 7˜10%.

11. Scouring and bleaching rove can be optional depend on the usage ofarticle.

12. Feeding in light measured weight, at low speed and the draw ratioshould not be too high.

13. Drawing machine preferably is an intersecting carding machine.

14. Spinning device preferably is a two bands system draft.

15. High temperature and relative humidity preferably is kept in thesefront processes. For example, the temperature preferably is 20˜30° C.and relative humidity is 65˜85%.

In this example, the natural bamboo fiber in a state of filament or thenatural bamboo fibers in a state of processed fibers are subjected tosliver, draw, rove and spin by means of linen spinning device such ascombined breaker and finisher card after said fiber being treated toimprove spinnability.

1. A yarn comprising natural bamboo fiber, wherein said yarn is preparedby spinning natural bamboo fibers alone or in combination with otherfibers in a blended ratio of natural bamboo fibers comprising 30 to 100%by weight and other fibers comprising 70 to 0% by weight.
 2. The yarnaccording to claim 1, wherein said natural bamboo fiber comprises anatural bamboo fiber in a state of filament, or a natural bamboo fibersin a state of processed fibers formed by remaining a certain amount oflignin and pectin on purpose.
 3. The yarn according to claim 1, whereinsaid natural bamboo fiber mainly has the following technology index: thenatural bamboo the natural bamboo fiber in a state fibers in a state offilament of processed fibers fiber count 1200 Nm˜2000 Nm more than 500Nm fiber strength 3˜5.5 CN/D 3˜5.5 CN/D average fiber length 30˜100 mm30˜100 mm nep less than 5/g thick ratio less than 0.5%


4. A process for manufacturing the yarn according to claim 1, whichcomprises preliminary producing step of the natural bamboo fiber andspinning step of the natural bamboo fiber, wherein further comprise astep of improving the spinnability of the natural bamboo fiber, and saidimproving step comprises: a. obtaining natural bamboo fiber; b.selecting natural bamboo fiber; in which the requirements for selectingnatural bamboo fiber are that the fiber should be straight and order;wherein the weight of fiber bundle changes in various species; c.providing oil to the natural bamboo fiber; in which the oil is a mixtureof soap with emulsification oil, wherein the amount of emulsificationoil is 1 to 1.8% by weight and the amount of soap is 0.5 to 0.9% byweight, both based on the weight of natural bamboo fiber; the oil isprovided by immersing the fiber into oil after humidifying treatment ata temperature of 80˜90° C. for 3˜4 hours in a bath ratio of 1:6˜8;wherein the emulsification oil comprises 47˜53% by weight of plant oil,0.04˜0.06% by weight of sodium hydroxide and 47˜53% by weight of water;and said plant oil has a acid number of less than 8, a saponificationnumber of 185˜195 and an iodine value of 76˜83; d. drying the naturalbamboo fiber in dryer after dehydrating it, the moisture regained afterdrying is 5˜9%; e. humidify by spraying and provide oil for the naturalbamboo fiber after the drying step, wherein the oil comprises 9˜10.6% byweight of kerosene, 0.3˜0.5% by weight of sodium carbonate, 6˜7.6% byweight of plant oil and 83˜84% by weight of water; f. stacking thenatural bamboo fiber for 5˜7 days after humidifying, the moisture of thefiber regained is 10˜15%.
 5. The process according to claim 4, whereinsaid spinning step of the natural bamboo fiber is carried out by usingthe technology of ramie spinning system in which the length of fiber isfrom 70 mm to 100 mm; and the step of producing yarns comprisespreparing natural bamboo fiber bundles by selecting, arranging,spreading, slivering, pre-drawing and combing the natural bamboo fiberby means of ramie spinning device after said fiber being treated toimprove spinnability, and then preparing yarns by drawing, roving andspinning.
 6. The process according to claim 4, wherein said spinningstep of the natural bamboo fiber is carried out by using the technologyof cotton spinning system in which the length of fiber is from 30 mm to50 mm; and the step of producing yarns comprises filaments producedduring the combing step or filaments produced as required by spinningare subjected to clear, scotch, roll, comb, draw, rove and spin (orrotor spinning) by means of cotton spinning device.
 7. The processaccording to claim 4, wherein said spinning step of the natural bamboofiber is carried out by using the technology of silk spinning system inwhich the length of fiber is from 65 mm to 100 mm; and the step ofproducing yarns comprises preparing natural bamboo fiber bundles byspreading, slivering, pre-drawing and combing the natural bamboo fiberby means of silk spinning device after said fiber being treated toimprove spinnability, and then preparing yarns by blending with spunsilk, roving and spinning.
 8. The process according to claim 4, whereinsaid spinning step of the natural bamboo fiber is carried out by usingthe technology of wool spinning system in which the length of fiber isfrom 65 mm to 100 mm; and the step of producing yarns comprisespreparing natural bamboo fiber bundles by slivering, pre-drawing andcombing the natural bamboo fiber by means of wool spinning device suchas comber after said fiber being treated to improve spinnability, andthen preparing yarns by blending with wool sliver, roving, spinning,grooved drumming, combining and twining.
 9. The process according toclaim 4, wherein said spinning step of the natural bamboo fiber iscarried out by using the technology of linen spinning system in whichthe length of fiber is from 50 mm to 100 mm; and the step of producingyarns comprises the natural bamboo fiber in a state of filament or thenatural bamboo fibers in a state of processed fibers are subjected tosliver, draw, rove and spin by means of linen spinning device such ascombined breaker and finisher card after said fiber being treated toimprove spinnability.
 10. The process according to claim 4, wherein themoisture of the fiber regained in stacking step f is between 10% and15%.
 11. The process according to claim 4, wherein the draw ratio iscontrolled between 5 and 10 in the step of slivering, drawing androving.
 12. The process according to claim 4, wherein the draw ratio iscontrolled between 10 and 30 in spinning step.